This invention relates to a plastic screw socket of the class used for providing engagement of a setscrew with a metal panel as when another metal panel or some other part is fastened onto the metal panel through the medium of the setscrew.
More particularly this invention relates to an improvement in and concerning a plastic screw socket which comprises a flange designed to be brought into contact with one surface of a given panel and a divided leg extending perpendicularly from the lower surface of the flange and adapted to be inserted through a matched perforation bored in advance in the panel, whereby helical insertion of a setscrew into a through hole axially pierced in the flange and the divided leg throughout their entire heights causes the divided leg to bulge outwardly and, by virtue of this bulging, come into tight engagement with the perforation in the panel so as to enable the setscrew driven into the through hole to be fastened to the panel.
Screw sockets of an operating principle such that helical insertion of a setscrew therein causes their divided legs to be brought into tight engagement with the perforation bored in panels and thereby enables the setscrews to be fastened to the panels through the medium of the sockets are extensively employed as screw receivers for the purpose of attaching parts to cabinets or automobile bodies.
Such a conventional screw socket has its leg divided by two slits inserted longitudinally therein from the lower end of the leg upwardly to the lower surface of the flange opposite each other across the through hole pierced axially therein, whereby the setscrew helically inserted into the aforementioned through hole causes the divided leg to bulge out in perfect symmetry and come into tight engagement with the inner wall of the perforation in the panel.
The conventional screw socket constructed as described above accomplishes its role perfectly by allowing the setscrew to be fastened to the panel. Since the leg, on being diverged by the insertion of the setscrew, bulges out symmetrically as described above, the two slits are opposed to each other across the through hole to divide the leg into two segments. In other words, the leg is divided into the two segments by the two slits which are longitudinally inserted therein from the lower end of the leg upwardly in one vertical plane which includes the axial line of the through hole. Thus, this screw socket has a possibility that the screw, on being helically inserted into the through hole, will accidentally find its way through either of the slits being diverged by the insertion of the screw and, consequently, the tip of the screw will thrust out of the periphery of the leg.
Under normal conditions, the screw which is helically inserted into the through hole advances on the axis of the through hole and causes the leg to bulge outwardly. Since the through hole which runs through the center of the leg opens sideways along the slits formed in the leg and further since the slits in the conventional screw socket are inserted in one common vertical plane that includes the axis of the through hole, there is a possibility that once the screw is accidentally inserted at a slight inclination from the axis under certain work conditions, the posture of the screw can no longer be corrected so as to coincide with the central line of the through hole and, as the result, the tip of the screw will find its way through either of the slits and eventually thrust out of the periphery of the leg.
Particularly in the case of an assembly line in which a multitude of parts are fixed in position by means of setscrews, it is difficult to enable all the setscrews driven into screw sockets of the construction described above to advance correctly on the axes of the through holes of the sockets. Besides, the emergence of the tip of the setscrew through the leg of the screw socket must be avoided because it has a fair possibility of inflicting damage to electric wires distributed within mechanical components under assembly and causing mechanical troubles.
A principal object of this invention is to provide a plastic screw socket which permits a setscrew to be quickly and accurately set in position therein without entailing a possibility of the screw finding its way into either of the slits being diverged by the insertion of the screw or the tip of the screw thrusting out of the periphery of the leg and consequently inflicting damage to the electric wires distributed inside mechanical components and causing mechanical troubles.